Bot Control example: Creating an exception for a blocked user agent

If traffic from some non-browser user agents is being erroneously blocked, you can create an exception by setting the offending AWS WAF Bot Control rule SignalNonBrowserUserAgent to Count and then combining the rule's labeling with your exception criteria.

The following rule uses the Bot Control managed rule group but overrides the rule action for SignalNonBrowserUserAgent to Count. The signal rule applies its labels as usual to matching requests, but only counts them instead of performing its usual action of block.

{
  "Name": "AWS-AWSBotControl-Example",
  "Priority": 5,
  "Statement": {
    "ManagedRuleGroupStatement": {
      "VendorName": "AWS",
      "Name": "AWSManagedRulesBotControlRuleSet",
      "ManagedRuleGroupConfigs": [
        {
          "AWSManagedRulesBotControlRuleSet": {
            "InspectionLevel": "COMMON"
          }
        }
      ],
	  "RuleActionOverrides": [
        {
          "ActionToUse": {
            "Count": {}
          },
          "Name": "SignalNonBrowserUserAgent"
        }
      ],
      "ExcludedRules": []
    }
  },
  "VisibilityConfig": {
    "SampledRequestsEnabled": true,
    "CloudWatchMetricsEnabled": true,
    "MetricName": "AWS-AWSBotControl-Example"
  }
}

The following rule matches against the signal label that the Bot Control SignalNonBrowserUserAgent rule adds to its matching web requests. Among the signal requests, this rule blocks all but those that have the user agent that we want to allow.

The following rule must run after the preceding Bot Control managed rule group in the web ACL processing order.

{
    "Name": "match_rule",
    "Statement": {
      "AndStatement": {
        "Statements": [
          {
            "LabelMatchStatement": {
              "Scope": "LABEL",
              "Key": "awswaf:managed:aws:bot-control:signal:non_browser_user_agent"
            }
          },
          {
            "NotStatement": {
              "Statement": {
                "ByteMatchStatement": {
                  "FieldToMatch": {
                    "SingleHeader": {
                      "Name": "user-agent"
                    }
                  },
                  "PositionalConstraint": "EXACTLY",
                  "SearchString": "PostmanRuntime/7.29.2",
                  "TextTransformations": [
                    {
                      "Priority": 0,
                      "Type": "NONE"
                    }
                  ]
                }
              }
            }
          }
        ]
      }
    },
    "RuleLabels": [],
    "Action": {
      "Block": {}
    },
    "VisibilityConfig": {
      "SampledRequestsEnabled": true,
      "CloudWatchMetricsEnabled": true,
      "MetricName": "match_rule"
    }
}